In practically all municipal wastewater treatment plants, waste water is separated into treated water and waste material. The waste material is in the form of a sludge comprising both solid and liquid material, the majority of the material being liquid. Before transporting the waste material from one location to another for further processing, it is advantageous to remove as much moisture or liquid from the sludge as possible, as this reduces the weight of the sludge. Also, the lower the percentage of moisture or liquid in the sludge, the lesser the chance of groundwater contamination due to seepage from the sludge.
It is known to initially de-water the sludge into a semi-solid sludge cake through drying and/or settling techniques. However, this sludge cake retains a substantial portion of moisture, requiring further treatment.
It is also known to employ compression apparatus, for example belt presses, filter presses, screw presses, centrifuges, in an effort to squeeze moisture out of the sludge cake. However, because of the consistency of the sludge cake, or due to the presence of certain polymers or flocculants within the sludge itself, it can be quite difficult to effectively eliminate moisture content beyond a certain level from the sludge. In general, conventional techniques are only capable of eliminating that level of moisture to achieve a moisture content of 75-80% in such waste material. Under further compression, the sludge tends to bind and ooze in any direction possible, effectively behaving like a hydraulic fluid.
A system for solving this problem would be considered an improvement in the art.